M6S2: Pharmaceuticals Of The Environment Flashcards
Adverse effects of pharmaceuticals in environment
-well known as preclinical and clinical studies establish both beneficial and toxic effects on humans
-so can predict adverse effects in drinking water for ex on human population but harder to predict effects on aquatic animals and plant life
Histology of air pollution problems (enter various ways)
Use in agriculture
-increases levels of antibiotics in groundwater and soil
-pharmaceuticals also used to treat farm animals, the agent is excreted, and resulting manure spread on fields as fertilizer
-can also lead to contamination of soil, ground water and eventually, waterways
Use in agriculture -> storage of manure -> manure spreading -> soil -> receiving water
Treatment of pets
-will be metabolized and excreted as they are in humans, and will find their way into surface and groundwater Systems
Treatment of pets -> soil -> receiving water
Disposal of medication
-about 25% of all unused drugs washed down the sink or flushed down the toilet, which find their way into sewage discharge
-30% of all unused drugs are thrown into garbage and disposed of in a landfill, which can contaminate groundwater
Disposal of medication -> soil -> receiving water
Aquaculture
-use of antibiotics in aquaculture (ex. Raising fish in enclosed spaces) is extensive
-prevent disease and to promote rapid growth to maturity
As aquaculture is concentrated at certain locales, high local concentrations of antibiotics may exist
Treatment of aquatic species -> receiving water
Human prescriptions
-administration and excretion of prescription drugs is one major source of pharmaceuticals is enviro
- a percentage of all drugs consumed by humans are excreted unchanged or as active metabolites
-these excreted drugs passed into municipal water systems
-treatment of sewage may or may not remove the pharmaceuticals prior to entry of treatment sewage into environment
Human prescriptions -> wastewater treatment -> receiving water
Manufacturing processes
-major effect in local surface and groundwater
-impact of this source of pharmaceutical release on environment will increase over time, as chemical facilities are moving to developing countries that have less environment standards than North America
Manufacturing processes -> wastewater treatment -> receiving water -> soil
*refer to goodnotes
Major classes of pharmaceuticals in the environment: neuroactive drugs
Includes: antiepileptics, and antidepressants like selective serotonin reuptake inhibitors (SSRIs) and antipsychotics
-use has increased by 60% over last decade
-drugs have been detected in surface water, groundwater, and soils
-sewage treatment plants reduce but do not effectively remove this group of drugs from effluent
-exposure of humans to neuroactive drugs in environment minimal (like with all)
Concern = concentrations of SSRIs present in surface water have deleterious effects on reproduction and physiological development of fish
Major classes of pharmaceuticals in the environment: steroid hormones
-most concern are estrogen IVC compound like ethinyl estradiol from oral contraceptives and excretion of natural estrogens by animals, including humans
-concentrations of steroid hormones in environment and drinking water are in ng/L range, which well below level where effects observed
2 major concerns:
1. Additive effect -> additive effect of human exposure to estrogens and endocrine distrupting agents (ex. BPA)
2. Reproduction and maturation -> deleterious effect of low concentrations of steroid hormones on reproductive capacity and sexual maturation of aquatic animals (ex. Ethinyl estradiol can inhibit fish reproduction at conc as low as 1 ng/L)
Major classes of pharmaceuticals in the environment: antibiotics
-very commonly prescribed drugs but major source in environment from agriculture, where these agents are added to feed to enhance animal growth (can effect us through biomagnification and all)
Major classes of pharmaceuticals in the environment: antihypertensive drugs
-around 30% of Canadians treated daily for hypertension, number will increase as population ages
-most measured in surface water, the concentrations are in the ng/L range which below toxic for humans
-unclear if these compounds biomaginified into food chain and what concentrations are present in seafood we eat
Major classes of pharmaceuticals in the environment: analgesics
-most common found in enviro from high frequency of use: ibuprofen, naproxen, and acetylsalicylic (ASA)
Risk on human health: no risk
Risk on aquatic species: minimal
Human risk assessment of pharmaceuticals in environment
-2 potential risks: drinking water and bioaccumulation in food sources
-standards for permissible levels of pesticides in drinking water exist but no regulations, same true for food sources
Concentration of pharmaceutical in environment
Factors:
-extent of use
-dose administered
-persistence in environment (ex. Half-life of pharmaceutical in environment weeks or years?)
-ability of Sewage treatment to remove agent
Minimum therapeutic dose used to determine the risk of various concentrations of pharmaceutical in environment to humans
How to calculate fold difference
Fold difference = minimum therapeutic dose/ daily intake
What group of drugs does minimum therapeutic dose for risk assessment fail
Anticancer drugs as significant toxicities occur at minimum therapeutic dose
-different uncertainty factor needs to be employed for risk assessment of cancer chemo therapies
Ideas of how to reduce potential risk of pharmaceuticals in environment to humans and other species
-reducing discharge from factories by altering manufacturing regulations to protect environment
-considering the potential effect of pharmaceuticals on environment as part of drug licensing process (requirement in some countries)
-municipal sewage treatment plants could be designed to remove or destroy pharmaceuticals in wastewater prior to discharge. Modern treatment plants are effective in removing some common drugs from wastewater
-expanding “take back program” at pharmacies for proper disposal. Unused pharmaceuticals must not be discharged into sewers and landfills
